In /etc/sysconfig/network on our HA system it says:
# Modified by FreePBX HiAv # It is critical that you DO NOT CHANGE THE HOSTNAME OF THIS MACHINE # Changing the hostname will cause the cluster to fail. NETWORKING=yes HOSTNAME=freepbx-a GATEWAY=10.44.1.254 # We're not joking about not changing the hostname. Don't change it # End Config
So it seems changing the hostname is a bad idea, but can a domain be added to make it a FQDN like freepbx-a.mydomain.com?